Calipers for rope and the like.



P. M. STEGMAIER. OALIPERS FOR ROPE AND THE LIKE.

APPLICATION FILED my 7, 1913.

1, 1 05,21 7. Patented July 28, 1914.

WI TNE55E5 /NVEN TOR M mm 5 Y W A TTYS PHILIP M. STEGMAIER, or PLYMOUTH, MASSACHUSETTS, ASSIGNOR T0 PLYMOUTH CORDAGE COMPANY, OF MASSACHUSETTS.

Specification of Letters Patent.

PLYMOUTH, MASSACHUSETTS, A COR ?ORATIO N 0F GALIPERS roRnoPE AND THE/LIKE.

Patented July 23, 1914.

Application filed May 7, 1913. Serial No. 766,021.

To all whom it may concern Be it known that I, PHILIP M. STEGMAIER, a citizen of the United States, residing at Plymouth, in the county of Plymouth and State of lllassachusetts have invented new and useful Improvements in Calipers for Rope and the like, of which the following is a specification. This invention relates to improvements in calipers.

More particularly it relates to calipers for measuring diameter of rope.

Hitherto it has been customary to'get the size of rope by the use of calipers similar to those used by machinists, carpenters and others, the instrument having a coupleof blunt points adjustable'todilierent distances from each other, the distance between them being the diameter of the body measured. The inappropriateness of an instrument of this sort for measuring the diameter of rope is obvious, owing to the flexibility and uneven surface of rope and the spherical or bi-curved nature of the'crests, so thatthe true tip of a crestis hard todetermine, and the fact that opposite crests are not truly opposite to each other, but, so far as I am aware, no better instrument for calipering rope; has been known until the present in vention. y

It is theobject of the present invention to provide simple apparatus by which the diameter can be measured more exactly and easily, The invention accomplishes this by providing calipers that automatically select the true crests on each side of the rope, and project the levels of those crests to positions opposite each other where they can v,beconveniently measured, More specifically, the instrument has blocks" with two parallel plane surfaces of size and relation to each other suitable to embrace the rope that is to be calipered, and to touch two or more adjacent crests on one side and at least one crest on the other side of the rope. These three points, two in one plane and one in the other and parallclplane, determine the positions of theplan'es at a distance apart from each other whichis the true diameter of the rope and whichmay then easily be measured, by measuring the distance be tween, the planes at any convenient place. The blocks supporting these planes may be other ing partsof the calipers. 'nection illustrated consists which are duplicates of each other, Each has a part which runs through one of the blocks for a suitable distance in a journal or bearing/ 12, arrangedparallel to the'adjacent plane ing 12; a

, port on,

connected together by any means that al lows the distance between themto be easily varied without their departing from paral 'lelisms The form at present preferred is thatv of simpleparallel links, having long bearings through the blocks, parallel to each and to said planes. .A sealemay be added,- pivoted on one of the blocks and adapted to lie parallel with the planes when the apparatus'is iclosed, and perpendicular to them when ready for use. Devices may be added to cause this scale to assume its the calipers are closed or openedyand this scale may he graduated to show both the dla'meter and thecircumference of therope at 'a glance; l

' In "the accompanying illustrate an embodiment Figure 1 is a perspective drawings, which of the invention, vviewed with the the calipers closed tive showing the calipers in use.

position automatically and correctly when vvaye on a level between two planes; Fig. 2 -1s an elevation showing as when not in use; and Fig. 3is a perspec- In the drawings, 10,lO repres entblocks of v wood or metal having plane surfaces ll, 11', I which face each other and are maintained always parallel to'eachother by theconnect- 1 The specific ,C,Qn M

of links 12, 12,

1 1 and parallelto the otherbear- I similar part inasimilar bearing in the otherblock; and the connecting link tions. .The journaled portions of onelink connecting these two j ournaled .por-* ssh are the same distance apartas the similar portions of the other link; and the journals are the same distance apart in one of the blocks 10 is in the other blockliO; so that a p parallelogram is formed. {The journals are long, and the links are sufiiciently strong or stifl' so that no'looseness originally existing, or whichmay be developed by wear, is

sufficient to allow any appreciable variation of the adjacent planes 11 from parallelism with each other; and'so that theparts' of the anyordinary. forcebebent out of parallel- I links resting in the jour nals 12' -cannot by planes which constitute the operating surfaces of the calipers are hinged at their edges, as it were, and are retainedpermanently in parallelism. If a piece of rope be then laid anywhere between these planes, and the two blocks be pressed together upon it, the planes will automatically select the extreme points on each side of the rope for their bearing. This is because the plane on one side, having come to a bearing on two or more crests, and being thus alined in parallelism with that side of the rope, does not touch any part of a strand on that side that is nearer the axis of the rope. The plane bearing on the other side of the rope being parallel with the first plane cannot touchanything but the single point that is most remote from the first plane, or all of the points that are equally most remote therefrom, all of which are likewise crests. It is assumed of course, that the rope being measured has first been drawn straight; but if not straight that fact will be evident to a person sighting between the planes, and the rope can be made straight by pressing the blocks together, provided the planes are long enough to engage several crests on each side of the rope.

. planes are made long enough to cover several crests of the rope strands, but it is suificient if they be only long enough to engage two crests of one side and one of the other, and this is particularly important in the case of rope of large diameter. The planes 11 should be wide enough to reach transversely past the center of the largest rope that is to be measured by the instrument, enough for the user to see clearly that the planes thus project beyond the crest.

The calipers illustrated further comprise a measuring scale 13 from which the di-" ameter or circumference of the rope can be read directly, and'automatic means to control this scale. The scale is pivoted at 11 on one of the blocks, and is adapted to swing on said pivot between a position of parallelism with and perpendicularity to said planes 11, shown respectively in Figs. 2 and 3. A stop 15 is provided, which is carefully located with respect to the position of the pivot 14 and the edge of the scale which abuts against it, so that when this scale is in engagement with this stop its edge is perpendicular to the planes 11. The scale then has its zero graduation precisely at the level of the surface 11 on the block 10 to which it is pivoted, and consequently the distance marks thereon show directly the diameter of the rope that is beingmeasured; inasmuch as the other plane projects in parallelism from the opposite side of the rope directly to the edge of this scale.

The scale is preferably of such width that it can behoused or protected by lying fiat along the edge of the block 10. The block Therefore, preferably the may'carry a spring 16 adapted to engage either the side or the end edge of the butt end portion of the scale, to hold the scale either housed or opened. This returns the scale against the stop 15, if it be accidentally moved away while the calipers are in use, thus making the instrument self correcting. To this purpose, the butt end of the scale is not strictly rectangular but is slightly oblique, as illustrated, so that the tendency of the spring is always to press the scale against the stop 15, thus insuring its perpendicularity to the two planes. This scale may be arranged either on the same side of the apparatus where the links are, as illustrated, or may be on the opposite side; and the edges of the blocks 10 may have superficial recesses, 17 18, adapted to receive the scale. 1 The recess 17 on the block 10 to which the scale is pivoted, affords a sort of housing for it. The bottom of the recess 18,

on the other block 10, affords a parallel positioned surface over which the end of the scale may travel; and the shoulder or abutment 19 at one end of the recess 18 is in position to engage the end of the scale and swing it into closed position automatically when the two blocks 10 are swung together into the position of Fig. 2.

The graduations on the scale may be in linear measure. according to the actual distance of the planes l1 apart, to show diameter of the rope, or may be marked with the proper multiple thereof to show circumference of the rope. The accuracy of the measurement can be easily tested, first, by sight ing through and observing how the rope lies between the planes 11, and whether all crests are touching; and second, by other readings, taken in order to strike an average, by rotating the rope on its own axis while it is in position and observing the readings at the different stages of rotation. This gives a quick ocular, and an easily measurable, indication as to whether the diameter originally read is the average diameter and to, what extent the diameter varies in the same part of the rope. Fig. 3, while professing to be a perspective, has been distorted somewhat to illustrate this visual characteristic, in that the top of the rope, which really should be seen in the middle back ground, '5. 0., touching the upper plane about midway between its front and rear edges, and so somewhat hidden by the front portion of the upper block, has been represented as if in proximity to the front edge of the upper plane 11, as it would be seen if the eye were at the level of the upper plane 11, although the remainder of the figure is perspective.

To use the calipers, a person swings the blocks apart on their links 12 until the scale automatically assumes a position of perpendicularity, lavs the rope between them,

, and then continues the swing of the blocks tion of the scale 13 from on their links until the rope is engaged between the planes 11. A catch 20 may be fixed on the other block 10, its edge being near the shoulder 19 of recess 18, the catch projecting in position to engage around a pin 21 fixed in suitable position on the scale 13. lVhen the calipers are closed, from the position of Fig. 3 toward that of Fig. 2, this catch first assumes a position with its hook under the pin, and then, as the rotaperpendicularity into parallelism with block 10 progresses, this catch and pin become engaged together. When the calipers are next opened, the catch 21 operates to draw the scale 13 out of its position of parallelism; and, before it lets go, it moves the scale far enough toward its position of perpendicularity for the spring 16 to take hold of it and to finish the movement of opening the scale. Thus the calipers adjust the scale automatically on closing, to a position of safety and protection, and on opening to the correct position for use; and the calipers themselves are automatic, when in use, in finding the proper points on the rope whose distance should be measured for getting the diameter of the rope, and in projecting that distance'to a place where a scale can be applied, and in indicating visibly the variations of the rope in diameter at any given place, when the rope is rotated in situ. Coupled with these advantages in use, it is to be noted that the calipers can be manufactured at small expense with sufiicient accuracy for ordinary uses. The plane surfaces 11 having been formed, the bearings can be drilled parallel thereto. The links may be each a piece of heavy wire, subjected to a single operation of forming with a die so that long portions at each end are bent into precise parallelism to each other, with the incidental result that the die-formed center portions of the links are of identical length. The ends may then be inserted in the bearings, and the terminals headed over as rivets.

I claim as my invention: I

1. Rope calipers comprising two plane faced blocks combined with linkage joining the edges of said blocks and maintaining said plane faces toward and parallel to each other, said plane faces being adapted to bear upon opposite sides of a length of rope, one plane face engaging a plurality of crests on one side of the rope and the other plane face engaging a crest on the other :side, whereby the diameter of rope whose crests are not diametrically opposite is indicated by the distance between the plane faces.

2. Rope calipers comprising two blocks having plane surfaces facing each other and adapted to bear upon opposite sides of a length of rope, one plane face engaging a plurality of crests on one side of the rope and the other plane face engaging a crest on the other side, whereby the diameter of rope whose crests are not diametrically opposite is indicated by the distance between the plane faces, and said blocks being provided with long bearings extending parallel to each other through the blocks; combined with links, parallel to each other, and each having integral portions comprising pivots in said bearings.

3. Rope calipers comprising two blocks having plane surfaces facing each other and adapted to bear upon opposite sides of a length of rope, combined with links holding the plane surfaces parallel to each other while movable to and from each other, a scale mounted on one block and movable between parallelism with and perpendicularity to a said plane surfaces, and means on the other block to engage and setit when the blocks are moved. 1

Signed by me at Boston, Mass, this thirtieth day of April, 1913.

" PHILIP M. STEGMAIER. Witnesses:

EVERETT E. KENT, ANNA B. LINDSAY.

Copies of this patent may be obtained for he cents each, by addressing the Commissioner Washington, D. G.

of Patents, 

